xprtrdma: Fix handling of RDMA_ERROR replies

mainline inclusion
from mainline-5.8-rc3
commit 7b2182ec
category: bugfix
bugzilla: 51800
CVE: NA

---------------------------

The RPC client currently doesn't handle ERR_CHUNK replies correctly.
rpcrdma_complete_rqst() incorrectly passes a negative number to
xprt_complete_rqst() as the number of bytes copied. Instead, set
task->tk_status to the error value, and return zero bytes copied.

In these cases, return -EIO rather than -EREMOTEIO. The RPC client's
finite state machine doesn't know what to do with -EREMOTEIO.

Additional clean ups:
- Don't double-count RDMA_ERROR replies
- Remove a stale comment
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: <stable@kernel.vger.org>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NLiu Jian <liujian56@huawei.com>
Reviewed-by: NYue Haibing <yuehaibing@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

net/sunrpc/xprtrdma/rpc_rdma.c

@@ -1203,8 +1203,7 @@ rpcrdma_decode_error(struct rpcrdma_xprt *r_xprt, struct rpcrdma_rep *rep,
 			rqst->rq_task->tk_pid, __func__, be32_to_cpup(p));
 	}
 
-	r_xprt->rx_stats.bad_reply_count++;
-	return -EREMOTEIO;
+	return -EIO;
 }
 
 /* Perform XID lookup, reconstruction of the RPC reply, and
@@ -1249,13 +1248,11 @@ void rpcrdma_complete_rqst(struct rpcrdma_rep *rep)
 	spin_unlock(&xprt->recv_lock);
 	return;
 
-/* If the incoming reply terminated a pending RPC, the next
- * RPC call will post a replacement receive buffer as it is
- * being marshaled.
- */
 out_badheader:
 	trace_xprtrdma_reply_hdr(rep);
 	r_xprt->rx_stats.bad_reply_count++;
+	rqst->rq_task->tk_status = status;
+	status = 0;
 	goto out;
 }